Abstract
We study the double exchange in transition metal oxides with itinerant and localized electrons. We show that the charge transfer energy and the oxygen-oxygen hopping amplitude have a strong effect on magnetic ordering: while for the ground state is ferromagnetic, for negative and large the double exchange gives rise to an incommensurate helicoidal ordering of local spins, observed, e.g., in the iron perovskites and . For negative , the metal-insulator transition into a charge-ordered state has little effect on magnetic ordering. This explains the difference in magnetic and transport properties of ferrates and manganites.
- Received 31 August 2004
DOI:https://doi.org/10.1103/PhysRevLett.94.137205
©2005 American Physical Society